HELP! Does this sound reflux?

My son is 6 weeks old and has been formula fed since he was born. Right from the beginning he has been quite a big eater and was eating 3-3.5 oz at 2 weeks every 3 hours. At the time he had minimal spit up, but often seemed to spit up and swallow it. He has now been eating 4 oz every 3 hours for about 2 weeks. Though the last few days he all the sudden can go almost 4 hours. We’ve tried doing smaller feedings more frequent with no luck as well. We burp frequently too, but he has a lot of delayed burps like if he has been lying down for an hour, we’ll pick him up and he’ll burp.

The spit up has definitely increased though it’s not projectile. He coughs/gulps when he is fed despite being on the slowest flow nipple for Dr. Brown’s bottles. He is on Enfamil’s Infant formula and has constant problems with gas. We tried Gentlease when he was just over a week old and he had issues pooping so we reverted back to the infant. He constantly seems uncomfortable, grunts through out the entire night and arches his back frequently. The nurse at my pediatrician’s office doesn’t think it’s reflux because there’s no projectile spit up.

This past few days has been horrible for us and he cries every time he is fed. He is spending 90% of his day swaddled or else he is in major meltdown mode. He also can’t stand being flat on his back.

I am at my wits end and plan on calling the doctors office again in a few minutes. The last time I spoke to them the only answer I got was that at 6 weeks all of these gastrointestinal issues would go away because his system would be more mature.

He just spent the last hour grunting and is only comfortable if he’s held. Is this consistent with reflux babies? I don’t think he has a severe case, but I definitely think he is on his way to developing something.